If you're not already familiar with Project Gutenberg you're missing out! It's the largest repository of free historical online texts and they're all provided completely freely to the world. A truly remarkable initiative.
I'm going to provide links, over the course of the next few months, to many historical texts that are relevant to the study of the sword starting with De Bello Gallico - The Gallic War by none other than Julius Caesar. It is a remarkable first hand account of Ancient Warfare, and while I will not pass judgement here on Caesar's War with Gaul I am certain that readers will find the details of his campaign to be very raw.
You will find De Bello Gallico here, available in numerous formats including Kindle, Plain Text, Epub and many more: